• Proceedings of the Korean Geotechical Society Conference
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• 2000.11a
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• pp.303-310
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• 2000

A new stress path testing scheme with back pressure equalization process is proposed, to compute the settlement of clay soils based on their probable deformation mode. The proposed testing scheme minimizes the efforts for testing, otherwise numerous testing works are required to simulate the probable stress paths in the field. Furthermore, the proposed testing scheme can supply anisotropic stress paths for consolidation which cannot be possible in a conventional way. The validity and effectiveness of the proposed testing scheme was investigated and confirmed with test results on remolded kaolinite clay soils. Conclusively, it is suggested that the proposed testing scheme is a very effective tool to compute settlement of clay soils and it is also very useful to investigate the anisotropic characteristics of deformation of clay soils.

• Geomechanics and Engineering
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• v.20 no.6
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• pp.505-516
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• 2020

In recent years, Nano-technology significantly invaded the field of Geotechnical engineering, particularly in soil stabilisation techniques. Stabilisation of weak soil is envisioned to modify various soil characteristics by the addition of natural or synthetic materials into the virgin soil. In the present study, laboratory experiments were executed to investigate the influence of nano-silica particles in the consistency limits, compressive strength of the soft clay blended with cement. The results revealed that the high compressibility behaviour of soft clay modified to medium-stiff condition with fewer dosages of cement and nano-silica. The mechanism behind the strength development is verified with the previous researches as well as from Fourier Transform Infrared spectroscopy (FTIR), X-ray diffraction test (XRD) and Scanning Electron Microscopy (SEM) analysis. Based on the results, the presence of nano-silica in soft clay blended with cement has a positive effect on the behaviour of soil. This technique proves to be very economical and less detrimental to the environment.

• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1357-1361
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• 1998

It has been shown that the physical properties of three anti-caking conditioners added garlic powders can be monitored and evaluated by some tests. The test parameters obtained are all quantifiable for powders fundamental properties. It is clear that cellulose powder and calcium carbonate are not attributed to the particle surface improvement effects. When SSA added 2% (w/w) for garilic powder which is improved flow ability and attractive index. Bulk density and compressibility were more sensitive indices to changes occurring in some conditioner added garlic powders.

• Magazine of the Korean Society of Agricultural Engineers
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• v.24 no.3
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• pp.84-91
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• 1982

This study was conducted to investigate the consolidation characteristics of repeated increasing and decreasing load m marine clay. Consolidation test was performed by the whole repetition of increasing and decreasing load and the partial repetition of increasing and decreasing load. The results obtained were as follows: 1. The void ratio e was decreased according to the increase of preloading and the repe- tition of increasing and decreasing load. 2. In case of the partial repetition of increasing and decreasing load the compression index Cc was decreased with the increase of preloading and the repetition of increa- sing and decreasing load 3. The expansion rate was greatly increased with the whole repetition of increasing and decreasing load and it was inclined to be increased with the increase of preloading in case of the partial repetition. 4. The coefficient of volume compressibility were decreased according to the repetition of increasing and decreasing load 5. The secondary consolidation coefficient was decreased with the repetition of increasing and decreasing load. Especially in case of the partial repetition, the peaks of secon- dary consolidation curves could be found to move toward the vicinity of preloading.

• Journal of the Korean GEO-environmental Society
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• v.22 no.12
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• pp.25-32
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• 2021

Geotextile tube technology has been perceived as an economical solution for liquid sludge treatment, and analyzing its consolidation behavior is necessary to be able to evaluate the dewatering capabilities of large geotextile tubes filled with contaminated soil, tailings, sewage sludge, and so on. The objectives of this study are to present a method that can adequately convey the consolidation behavior of geotextile tubes filled with sewage sludge, and to investigate the effects of various geotextile tube consolidation parameters. In this study, variable coefficients of consolidation are utilized to analyze the consolidation process of geotextile tubes filled with sewage sludge. The consolidation solution was verified by comparing the measured and predicted data from a hanging bag test conducted in the literature. After verifying the proposed solution, the consolidation parameters of a geotextile tube composed of a woven polypropylene outer layer and a non-woven polypropylene layer filled sewage sludge were obtained. Using the obtained parameters, the consolidation behavior of a large-scale composite geotextiles tube was predicted.

• Geomechanics and Engineering
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• v.15 no.6
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• pp.1143-1151
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• 2018

Loess often causes problems when used as a filling material in the construction of foundations. Therefore, the compaction technique, shear behavior, and bearing capacity of a filled foundation should be carefully considered. A series of tests was performed in this study to obtain effective compaction techniques and construction parameters. The results indicated that loess is strongly sensitive to water. Thus, the soil moisture content should be kept within 12%-14% when it is used as a filling material. The vibrating-dynamic combination compaction technique is effective and has fewer limitations than other methods. In addition, the shear strength of the compacted loess was found to increase linearly with the degree of compaction, and the soil's compressibility decreased rapidly with an increase in the degree of compaction when the degree of compaction was less than 95%. Finally, the characteristic value of the bearing capacity increased with an increase in the degree of compaction in a ladder-type way when the degree of compaction was within 92%-95%. Based on the test data, this paper could be used as a reference in the selection of construction designs in similar engineering projects.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1200-1205
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• 2010

The compression index is one of the geotechnical properties which represent the compressibility of clay. The compression index are generally obtained from consolidation tests, otherwise it has been predicted by soil properties due to the efficiency time and cost. In this study, consolidation tests result for Busan and Inchon clays are analyzed to suggest the correlations between the compression index and soil properties. It is found that the compression index is well correlated with the void ratio and natural water contents. The prediction errors, which is difference of compression indices between measured from consolidation test and predicted by liquid limits, decrease with ${\Delta}e_0/e_L$.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.449-456
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• 2009

As soft grounds have complex engineering properties that the load bearing capacity is low and high compressibility, it needs to solve this problems prior to structures are constructed by the method of improvement of soft ground. Generally, the sand mat is used to as a horizontal drain material and loading base for soft ground improvement work. However, as the natural environment can be damaged by sand pickings of large quantity and the volume which is enormous and an amount of demanded sand is increased, it is state of short in supply. This paper presents the result of field experimental test to use Precious Slag Ball to solve these issues instead of sand mat as the replacing material. This study evaluated the performance of Precious Slag Ball as a sand mat in terms of discharge capacity, settlement, and settlement through the K-Embank program.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.6
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• pp.36-44
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• 2021

Numerical analysis was performed on the shock wave-boundary layer interaction generated in the internal flow path of the curved interstage of the scramjet engine flight test vehicle. For numerical analysis, the turbulence model k-ω SST was used in the compressibility Raynolds Averaged Navier Stokes(RANS) equation. Representatively, the separation bubbles on the upper wall of the nozzle, the interaction between the concave shock wave and the boundary layer, and the shock wave-shock wave interaction at the edge were captured. The analysis result visualizes the shock wave-boundary layer interaction of the curved internal flow path to enhance understanding and suggest design considerations.

• Journal of the Korean GEO-environmental Society
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• v.14 no.9
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• pp.57-65
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• 2013

Carbonate sands can be crushed under low confining pressure to achieve high compressibility. So particle crushing has significant influence on characteristics of strength and deformation. Trial embankment and hydrotest are conducted on Sabkha layer, consisting of carbonate sand to build tank structure. In this paper the settlement behavior was analyzed from each test. Particle crushing happened from 80 to 170kPa stress under compression test, and calcium was detected from chemical test. The test result came out Sabkha soil was very weak and easy to be crushing. About trial embankment test, particle crushing was not happen, and then extinction of pore water pressure and settlements were finished just during 2 days. On the other hand, the long-term settlement was happened in hydrotest. So the two test results did not correspond to each other. If loading stress is higher than yielding stress, instant settlement and secondary compression settlement are happened as a result of the particle crushing.